


detox just to retox

by nilchance



Series: ain't this the life [8]
Category: Undertale (Video Game)
Genre: M/M, Sex as Coping Mechanism, Underfell Papyrus, Underfell Sans, cross-universe bullshit shenanigans, detailed content notes in the end notes, kustard - Freeform, offscreen fellcest
Language: English
Status: Completed
Published: 2018-05-24
Updated: 2018-05-24
Packaged: 2019-05-13 11:31:41
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,820
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14748000
Author URL: https://archiveofourown.org/users/nilchance/pseuds/nilchance
Summary: Before Red even opens his mouth, Sans says, “Not tonight.”





	detox just to retox

_”You’re being so good for me.” A pause, Red’s hands on him, Sans wavering on the edge of bolting. It’d be easier if Red just pushed forward, plausible deniability, a way for Sans to be able to meet his own eyes in the mirror later, but Red doesn’t. He makes Sans complicit. “That okay?”_

_No. It’s not okay. It’s not okay for Red to see through him. It’s not okay to let Red do this to him. It’s not okay to be this hungry for anything. It’s not okay to want this so badly._

_But he does._

_Like a fool, Sans lets himself say, “Yeah.”_

***

When Red comes to Sans at night, after work or outside Grillby’s, they both know how it'll end. Sans responds like Pavlov's dogs, trained into doing a trick on command. As soon as he sees Red waiting for him in the call center parking lot, his body is screaming yes.

Before Red even opens his mouth, Sans says, “Not tonight.”

It’s easier than saying he’s done. That they’re done.

Nothing good comes of mistaking what he wants for what he needs because he always pays for it one way or another. Always. He’s been running on emergency power for months, dragging himself along through the days, waiting for it all to stop. He doesn’t have anything left in him to pay whatever this’ll cost.

Red cocks his head, his eyes bright. It’s hard to tell if Red knows that ‘not tonight’ means ‘not ever’. For a second, Sans thinks (hopes) Red will push him. He knows how to deal with people who get a little too pushy. Nobody's ever tried to force the issue, but there's been wheedling, tantrums, guilt trips about blue balls from people who were criminally ignorant of basic biology. Unusual but not unheard of. He's used to it by now.

Red only shrugs. "Cool. Maybe next time."

Sans relaxes a little. Red didn't ask for an explanation, but he offers one. "Figure I'll spend some time with Papyrus and then crash early."

“Tell him I said hi.” Tugging Sans's hoodie, Red reels him in and nuzzles his face. Sans can feel Red's mouth moving against his jaw, a shivery feeling. "How about when you’re in the mood to fuck around again, you come find me?"

It takes more effort than it should not to just grab Red by the back of the neck and take his mouth. He needs to get a handle on that. Sans keeps his hands jammed in his pockets. "Okay. Grillby's tomorrow?"

It's not like he's going to ditch Red now that they're not fucking. He enjoys the guy's company even if he sometimes wants to smother Red with his own hoodie.

Red pulls back to grin at him. "So long as you're paying."

"I always pay, you cheap dick," Sans says.

"My dick is priceless and that's real culturally insensitive of you," Red says. "Unless you _want_ me to offer you food. I'm sure I could find a collar around here somewhere."

"Yeah, no. I'll just put it on my tab." Sans steps back out of Red's reach. "Besides, you couldn't handle me."

"You love it when I handle you," Red says.

"Those are pity orgasms," Sans says. He needs to get that blushing thing under control, it’s embarrassingly obvious. Red's expression just gets more smug. Sans never realized exactly how irritating his smug grin is. It's amazing more people haven't tried to punch it off. "Seeya."

"Funny how pity orgasms get my dick just as wet as--" Red starts.

Sans leaves him in the parking, talking shit to no one.

***

Sans follows through for once. He happily soaks up a few hours of Papyrus's company, leaning against each other on the couch, and is in bed before midnight. He even falls asleep easy, for once, and stays that way. No lying awake with his soul aching in his chest. No nightmares. It's a miracle.

Three hours later, he wakes up soaked, his clothes clinging to his bones with sweat, his magic formed and aching. He doesn't get as far as jerking off. The first touch of his fingers on his dick and he's coming in his shorts like a teenager, seeing white, shoving his face in his balled-up hoodie to muffle his grunt.

He's sticky. He's humiliated. He's completely, utterly unsatisfied.

***

Three days.

Sans knocks against his mattress. It's soundless, but in his head he hears it as two dry little taps, like bone on wood. Knock knock.

Of course no one asks him, "Who's there?" It's 1:35 AM. He's in his bedroom with the door shut. Papyrus seems to actually be sleeping, probably worn out from the lecture about sleep hygiene and from trying to shove warm milk down Sans's throat. Sans been laying here for three and a half hours, staring at his ceiling, trying not to think of things. There are a lot of things he's trying not to think about. It's getting kind of complicated, navigating that minefield in search of safe topics. String theory. Pranks to play on Papyrus. Knock knock jokes.

Right. He left the person who didn't ask "Who's there?" hanging. Rude of him. He says, quiet, "Anita."

"Anita who?" nobody says. Nobody is really accommodating tonight.

"Anita good night's sleep," Sans says. He drapes his arm across his eyes. "Heh. 'Cause, uh, this is pretty fucking pathetic."

The lack of response doesn't seem particularly sympathetic.

Three days since he cut Red off. He made it six years barely thinking about sex, and it's not like he and Red were fucking every night since they started. Three days is nothing.

Red certainly doesn't seem to be suffering. They've had lunch twice. No flirting, no innuendo, no outright pornographic talk. No stealth touches to Sans's wrist, the small of his back, the nape of his neck. Red hasn't teased him. Red hasn't touched him at all, only watched him, half-lidded and grinning neutrally, telling dead baby jokes and stealing Sans's fries until Sans douses them in ketchup in self-defense. Just two guys being pals.

Red is giving him space, letting Sans make the next move. Even Edge has kept his distance, skipping his breaks with Sans with terse texts about there being too human bullshit right now for him to leave Asgore alone. Maybe when it becomes clear that this is the new normal, Edge will start coming back around. Maybe not.

The thing about space is that it's cold.

Which is ridiculous. Sans isn't addicted to Red's dick, for fuck's sake. He's fine. It's just chilly in here. (Bullshit. He hasn't been really warm in months.) His real problem is that he's slept five hours in two nights when he was already sleep deprived and if he drinks any more coffee to get through work, he'll see through time. It's like he's back in grad school.

... it's like he's back in grad school.

Sans sits up, looking at his alarm clock. 1:40. The bars are still open. It's coming up on closing time, the hour of lowered standards. Looking like Sans does right now, he can use all the help he can get. He shrugs his hoodie on and grabs his slippers. No need to wake Papyrus or disabuse him of the notion that when Sans says he's going to sleep and closes his bedroom door, he actually stays there the whole night.

"No, I got a better joke," he tells nobody. "Anita get laid."

It doesn’t have to be Red.

***

There’s a bar. There’s always a bar.

He shortcuts to three before he finally manages to find somewhere without familiar faces, which means it’s mostly humans. Nobody’s hassling the one monster steadily drinking human beer at the bar. She’s the only one who gives him a strange look when he comes in, but when he raises a brow, she shrugs, flashes him a peace sign and goes back to her cell phone.

Sans has never tried to fuck a human before, but he hasn’t lost his touch. He finds a likely prospect in two minutes, a bearded dude in flannel. The dude is all round belly and red beard and soft, short-fingered hands. A manageable height: bigger than Sans, but not as big as some of the monsters Sans has been with. No wedding ring, no LV. Hasn’t even hurt anybody. Seems like a nice guy. Totally unlike Red, aside from the crookedness of his smile. Sans buys him a drink, gives him a look and a grin, and the guy goes pink in the face. Then the guy bites his lip and gives Sans a long, speculative look back.

The thing about being a judge is that Sans knows himself too well. He knows exactly what kind of person he is, with no chance for comforting self-deception. Sans knows he's a failed scientist, a lousy brother and fundamentally useless all around, but sex? He's good at sex. He's never fucked that up. 

Ten minutes after Sans hits the door, he and the dude are in the cramped bathroom together, the door locked behind them, and Sans has his hand in the guy’s jeans.

It's easy to fall into the old rhythms of jerking off a stranger. There's a safe distance. Sans can watch the guy enjoy himself without the inconvenience of emotions. He feels nothing. No slow heat in his pelvis, no fast pulse in his ears, no heady combination of excitement and fear. Not even the old sense of smug accomplishment. Nothing.

Maybe he should stop if he’s not feeling it. But fuck it, he’s already got this far. He can’t leave the guy hanging.

A little spit for lube, a couple minutes of work, and the dude comes easy, biting his fist to keep quiet. Sans grabbed paper towels before they started and manages to keep any jizz from hitting the floor or getting on their clothes. Practice. It's different than the kind of fluids monsters produce, no faint tingle of magic. He's fascinated on a scientific level at the same time he wants it to wash it the hell off. The thought of licking it clean like he would with Red makes him a little nauseous.

"Thanks," the guy says when he gets his breath back. He's blushing, a dopey little smile on his mouth. Just another happy customer, not that Sans doesn’t give it away for free.

Sans says, "No problem, dude."

The guy takes a step forward. "Lemme--"

Sans doesn’t remember the resets. Small mercies. But sometimes he has those moments, bright and impermanent and disorienting as the flash of sunlight off a knife, and he has one now. He's stepping back before he means to. Suddenly he can feel the humanity of this guy, the difference in the resonance of his soul, the stronger organic scent of him. There the fear is, right on schedule, but there's no eagerness to balance it out. He's got no interest, none, negative interest in letting this guy get his pants off.

“Hey, it’s okay,” the guy says, immediately stopping, putting his hands up. His whole expression changes. It’s practiced, like the guy is used to dealing with skittish people. A shrink, maybe? A social worker? It doesn’t matter, but it’s something harmless to fixate on, so Sans lets that derail his thought processes back to safer ground.

"Sorry," Sans says. He heads to the sink, walking sidelong so he doesn't have to turn his back to the guy. He keeps his smile easy. "Got nothing for you to help me out with. Heh. What did you expect? I'm just a skeleton."

He can hear Red laughing at him.

There's some awkwardness. In the end, Sans is the one to walk out as soon as his hands are clean. He keeps walking out the bar, pausing to wink at the glowering bartender, and then into the alley beside it. Once he's alone, he lets the smile drop.

It didn't work. It didn't _work_. What is he supposed to do now?

Right on time, a voice comes from too close behind him. “Hey, lover. You’re--

Sans is halfway down the alley in a second, facing him. Red grins amiably at him and finishes, "-- out late. And a little skittish tonight, apparently."

Sans's soul is pounding. It's not just adrenaline. All the magic flowing through his body feels molten, a belated reaction to what he was just doing. He manages to keep it from forming something at the sight of Red, barely, but he can feel that sudden heaviness in his pelvis like anticipation. Three days worth of frustrated want, like Red edged him without even touching him. Apparently his body missed the part where Sans is trying to be smart for once.

"We've gotta talk about the ironic pet names before it gets even creepier," Sans says.

“Fuck you, I’ve never been ironic in my life.” Red wanders back into Sans's personal space, unhurried, like he knows Sans isn't going anywhere. Sans gets even more tense, somehow. It feels like his soul might pound itself to dust. Red says, "Thought you were supposed to be catching up on sleep."

Sans shrugs. "Tried. Couldn't."

"Been there," Red says. He could reach out a hand and touch Sans so easily. That potential vibrates between them, agonizing, but Red doesn't close the distance. "What’s the matter? You look really... unsatisfied."

Sans didn't see him in the bar. Sans would've seen him, wouldn't he? He's not that fucking tired. But one look at Red's expression and he knows Red knows.

“I didn’t make you any promises,” Sans says. For once, he doesn’t have a reason to feel guilty.

Red waves that off. "Don’t get it twisted. It'd be pretty damn hypocritical of me to be pissed, considering that Edge fucked me a couple hours ago."

"Gross," Sans says. What's actually gross is how rote that response is, the majority of his mind too occupied by how close Red is to him, the way he smells, how easily Sans could kiss him right now. Red just told him he had incestuous sex and it's not putting Sans off.

"I showered, you fucking pussy. My point is that you're a free bitch, baby. Although seriously, a human?” Red tsks like a disappointed schoolmarm. “What'd you get out of that besides a shitty-tasting protein shake?"

Sans thinks of the dude's face when he offered a blowjob and snorts. "It was fine."

Red bristles. “Hey, no, there’s no fucking way I get the same rating as some meatbag in a bathroom who didn't get you off.”

“Who says he didn’t get me off?” Sans asks.

Red gives him the look that that question deserves. “Did you even let him touch you?"

"No, Red. I jerked him off with my mind."

It's an invitation to snark at each other instead of having this conversation. Unfortunately, Red doesn’t go for it. "You didn't let him lay one finger on you. I can see it on your face. As soon as it ain’t me, you’re right back on your bullshit."

"Look, I don't wanna hear the ugly details of your sexcapades and you don't wanna hear mine," Sans says.

"Ha! Oh, you fucking bailed when he was done," Red says. "I knew it. Was it everything you wanted, sweetheart?"

“It was great, except for the part where you were lurking outside like a creeper,” Sans says. “How did you even know where I was? How much stalking should I be worried about here?”

“Don’t flatter yourself. I make it a point to know a lot of people, and sometimes they give me a call when they see something interesting,” Red says. “Like, say, a dude who looks like me in nerdier clothes wandering into the can with a human. You’re gonna ruin my rep.”

“I can’t ruin it much more than you do,” Sans says. He thinks of the monster at the bar and her cell phone. How many of these ‘friends’ does Red have, exactly? “When you said you had a job--”

Red puts a finger to Sans’s mouth. It’s the first time Red’s touched him in days. Sans shuts up, overwhelmed by the impulse to take that finger into his mouth, and Red winks at him.

Here Sans was figuring Red was Edge’s housebitch, and Red’s been quietly setting up an information network like a sneaky bastard. Not for the guard or the crown, although he may be getting paid by them, but for Edge. To keep Edge safe.

It’s probably fucked up that an incestuous murderer is a better brother than Sans has ever been.

“Anyway,” Red says smoothly, taking his hand back, “I figured I should check it out. Y’know. In case you needed something.” Red drags his gaze down Sans’s body and then back up again, slow and deliberate as a touch. “You need something?”

(Yes. Fuck everything, yes, he thinks he does.)

Sans doesn’t think his magic has formed anything but glancing down to check would be as much a giveaway as something glowing in his shorts. The streetlight is out this far down the alley and the neon bar sign doesn’t reach. It’s just the two of them in a patch of city darkness, lit only by their eyelights. In his pockets, Sans’s fingers are digging into the spaces between his metacarpals. He can hear his own shaky breathing. He doesn’t answer.

“No?” Red shrugs. “All right. Go home, dude, this ain’t a good part of town. You’re free EXP. You’re lucky I didn’t let Edge come fetch you like he wanted. See you--”

Sans grabs his arm. It’s involuntary, sheer panicked reaction to the rising ozone crackle of a shortcut opening. All his smart words dry up in his mouth and he just looks at Red, stupid and desperate.

The shortcut doesn’t fully close, a prickle against the back of Sans’s neck. It’s not safe to leave that door half-open too long. Red studies him, then asks almost gently, “You wanna go back to my place and have sex?”

All his good intentions, and Sans folds under the prospect of relief like a house of cards. Roughly, he says, “Yeah.”

Red chuckles. “All you had to do is ask.”

After the near darkness of the alley and the total black of the void, the comfortable dimness of Red’s living room makes Sans wince, though it doesn’t seem to bother Red. After a second, Sans sees why Red dropped them here. Edge is on the couch, folded up at sharp angles like a praying mantis. There's a stack of paperwork beside him that he's scowling at. Of all the things that Sans pictured when he thought of what Red and Edge got up to in private, it didn't involve paperwork.

Edge glances up at the sound of the shortcut. Sans's attention snags on the fact that Edge's boots are off. He's barefoot and his bones are very white against all that black leather. Sans is used to him being layered up, gloves and boots and jacket, from collarbone to toe. He should probably stop looking, it's getting weird.

"Uh," Sans says awkwardly. He just wanted a booty call, he's not prepared for dealing with Edge. He's never prepared for dealing with Edge. "Hey. Since when does the guard involve paperwork?"

“Strange, that’s exactly what Undyne said,” Edge says sourly. “Which is why there’s a three year backlog. Some asshole kept submitting daily reports with ketchup stains on them.”

“What a dick,” Sans says.

Red drapes himself against Sans's back, a sudden heavy weight that makes Sans stumble. Sans can't see it, but he's pretty sure Red is smirking at Edge over his shoulder. "Found him wandering. He followed me home. Can I keep him?"

"If you promise to feed him," Edge says. If he's irritated that Red dropped Sans in his living room in the small hours of the morning, he doesn't show it. It's like there's actually room for Sans in this weirdly domestic little scene. If Red wasn’t all over him, he’d bolt right then.

"I'm gonna feed him right now," Red says. Sans jabs his elbow into Red's ribs, because Red really needs to stop putting himself in this position, and Red just rubs his cheek against Sans's like a cat. "Y'know. My dick."

"Subtle as ever, brother." Edge returns his attention to the paperwork. Sans relaxes a little when Edge isn't looking at him. To Sans, Edge adds, "I’m not using him. You can borrow him."

"Yeah, Sans, borrow me," Red says, putting his hands on Sans's hips to push him towards Red's room. "Borrow me hard."

Sans has regrets. So many regrets. He lets himself be pushed. Red and Edge have a serious herding instinct. When the door closes, Sans turns to Red and whispers, "Dude, I don't know if I can do this with him just sitting out there."

"Why are you whispering?" Red asks, not bothering to drop his voice. Sans glares at him, and Red laughs. "He already knows we're fucking."

"Yeah, but--" Sans starts.

Red gets up in Sans's space, unzipping his jacket, backing him up towards the mattress. Sans’s magic drops heavily and with embarrassing abruptness into his pelvis. Red’s hands are on him again. The mattress is right there, clothes are coming off, and sweet relief is on the horizon. Sans shudders at how much more sensitive his magic is compared to bone, how much more urgent everything seems, and Red must feel it under his hands because his smile curves sharp as a scythe. 

All considerate, Red asks, "You wanna go to your place?"

"No.” Sans shudders for a different reason. “That's actually worse."

“Well, you’re not fucking me in a public bathroom, buddy. That’s weird.” The irony of Red saying anything is weird makes Sans snerk. Red puts both hands on Sans’s shoulders, stroking his clavicles through his shirts. It’s nowhere near where Sans wants his hands and Red knows it. “You still wanna do this?”

Even he’s not a good enough liar to say no. Sans nods jerkily.

Red hums, pleased, and leans forward to kiss him. Sans presses into it, fumbling to get Red's clothes off with Red’s enthusiastic help, only reluctantly breaking off to yank Red's shirt over his head. Then Red is naked, Sans mostly clothed, a fact that does things to Sans's higher brain functions. His hands roam Red's body, unable to settle, hungry for more warm bone under his fingers. He maps the lines of Red’s body like it’s unfamiliar territory, lingering on the places where Red is scarred and Sans isn’t, the differences between them.

Between kisses, Red says, "Then I guess you better be quiet, huh?"

Sans kneels and pulls Red down to the mattress beside him, trying to peel his shorts off at the same time. They should be talking. He should try to argue that this is still his turn, that last time didn’t count because honestly, even if this universe apparently doesn’t have half as much porn, Sans has heard of topping from the bottom, thanks. But Red is so warm against him. He can’t think straight. He doesn't want to let go. He wants to press close and soak up that heat, make it his, maybe take some of it with him when he goes back home.

He's messed up enough that he doesn't even know what exact equipment he's got going on between his legs until Red cups it in his hand, fingers slipping between the lips of Sans's pussy but not in him where he needs it. Sans shudders so hard it’s nearly a seizure, his hips jerking. Red makes a soft noise in his throat and says, his voice low, "Fuck, you’re all ready for me, ain’t you? I don’t gotta do a thing."

Sans laughs, cracked and a little high. “I didn’t miss the dirty talk.”

Which is too close to admitting he missed Red at all, but Red surprisingly lets that pass. He presses closer to Sans, one knee between his legs, keeping him open like Sans has it in him to resist. He slides two fingers in at once and Sans takes them easily, gratefully. He can’t stop shaking. He can’t be both silent and still at once. It’s too much. He has to vent the overwhelming amount of things he’s feeling before he strokes out.

"You're even wetter than you were that first time.” Sans almost can't hear Red over his own ragged breathing. Red gives him a third finger, pressing up and in, and Sans grabs convulsively onto Red’s shoulder. Red says in that soft, soft voice, "You think you could take my fist?"

Sans clamps a hand over his mouth, fast, muffling the sound he makes. He shakes his head no, not because he thinks Red couldn't (he can feel the wet sliding down the inside of his femurs) but because that's dirty pool. He can't take it. Red isn't giving him enough to get off on. He's only letting Sans rock against his hand, trying to get relief. Red is sitting just far back enough from him to see his face. It's hard to keep his expression under control when Red is three fingers deep in him.

"No, you're right," Red says, like Sans actually said words. "If we're doing that, I'm gonna take my time with you. Even you might get loud. How about you tell me what you want tonight? After last time, that's only fair, right?"

Sans would tell him where he could stick his sense of fair play, but he's afraid to uncover his mouth. He's going to kill Red after this, and then Edge will kill him, and it'll be a goddamn Shakespearean tragedy with more fingerbanging.

Red gives Sans a shallow thrust with his fingers, his palm grinding against Sans's clit. Sans jerks, nearly doubling over, and hates himself for the noise he makes when Red stops.

"You want my fingers?" Red asks. Even though Sans is being selfish as fuck right now, just letting Red touch him without trying to return the favor, Red sounds like he's eating this up. "Or do you want me to fuck you?"

And oh, fuck, Red is going to make him say it. Red just sits there, waiting him out. Sans hates him so much.

Whether he signs or speaks, he's gonna have to risk taking his hand off his mouth. He does it, prying one finger off at a time, and says hoarsely, "Fuck me."

It's quiet, but it's still the loudest thing either of them have said since they closed the door. Sans winces. Totally unconcerned, Red asks, "What's the magic word?"

"Now," Sans says through his teeth.

Red snorts. "Rude.”

Since Sans's hand is off his mouth and everything, he takes the opportunity to add, "I’m rethinking my stance on murder.”

"Thanks for the warning," Red says. He slides his fingers out and the sudden emptiness makes Sans regret every one of his sex intinery decisions. "Makes me doubt your commitment. Did you threaten to kill bathroom guy or am I special?"

As long as Red isn't touching him, it's safe for Sans to open his eyes and look at him. The flush at Red's joints and the feral anticipation of Red's grin makes Sans throb all over. He's staring like he’s never seen Red before. He swallows. "Bathroom guy didn't annoy the shit out of me."

"Yeah, I know." Red sucks his fingers clean with a lewd noise that makes Sans want to shove him over and ride his face. "Mmm. You were in control every second. But you didn't beg him to fuck you."

"I didn't beg you," Sans says, like he wouldn’t have if Red had asked. Sniping at each other is familiar ground. He untangles himself from Red so he can get on his hands and knees in the center of the bed. "I might beg you to shut up if I thought it would help. I--"

Red grins up at him from where he's flopped beside Sans. When Sans stops, staring at him, Red waves a hand. "No, go on, I love listening to you bitch at me. It's like you give a fuck about stuff for a minute."

Sans narrows his eyes. "Do I need to draw you a diagram?"

"Yeah, we're not doing that. Come down here."

"Did I get you addicted to the missionary position or something?" Sans demands.

Red snorts. "Bitch, please. Lay with your back to me."

Well. He can certainly suck up more of Red's body heat that way. They'll be spooning, which is weird, but it's a small price to pay for getting off. There's no question that Red will get him off anymore, just how hard and with how much unnecessary bullshit.

He lays down. Red snuggles contentedly against his back, then readjusts Sans's leg, angles himself, and pushes into him. Fills him, like a key sliding into a lock. It's just that fast. Sans jolts, his breath hitching in a stupid hiccuping noise.

"Ah, fuck," Red whispers, his grip tightening on Sans's leg. He thrusts experimentally, the angle deep and good, and Sans barely manages to bite back his moan at the last second. Red has the nerve to tell him, "Shh."

"I'm trying," Sans says, his best attempt at a snarl without actually raising his voice.

Red nuzzles the back of his neck, abusing the shit out of those extra few inches of height. “You want me to help?"

At this point, Sans needs whatever help he can get. He nods a little frantically.

Red reaches around him and puts his hand over Sans's mouth. Sans doesn't need to breathe, technically, but having one source of air taken away makes his head feel light and strange after a few seconds. But's one less thing Sans has to concentrate on, one less thing to worry about. Which is good, because he's been keyed up for so long and he really, really doesn't want Edge to hear this.

"That all right? Can you breathe okay?" Red asks. Sans fumbles a hand back, grabbing at Red's hip and trying to pull him forward, and Red laughs. "Okay. If you wanna stop, just grab my arm."

It's dangerously close to talking about safewords and all the bullshit that comes along with it, and there are alarm claxons going off in Sans's head, but, again, Edge in the living room. It's not kinky, it's common sense.

Red starts to fuck him. There's no frustrating warm-up, no preamble. Without Red's usual running commentary, the quiet is full of Red's soft grunts in his ear, the wet squelch of his cunt and all the muffled noises he can't keep back. He claws at Red's hip, trying to meet Red's thrusts, but he has almost no leverage in this position and even less if he lets go to rub himself off. That’s why Red insisted on it.

Red’s giving it to him hard and fast, exactly the way he needs it, without any bullshit. Sans doesn’t actually need leverage. He doesn’t need to push Red to get what he wants. There’s a sweet lassitude that wants to sink into him because he’s warm, finally, and he’s tired, and the mild oxygen deprivation is dulling the edges of his resolve. It seems stupid to struggle when he’s let so many other worse things happen without a fight. He could just relax and take what Red gives him, and it would get him there. It would be so good.

The definition of insanity: putting himself in Red’s bed again and again and somehow expecting to keep his shit together.

He keeps pushing back, trying to at least feel like he’s in control of something. It doesn’t get him anywhere but he keeps at it. Red’s voice isn’t in his ear, mocking and coaxing him along, but Sans can’t lose track of where he is or who he’s with when Red is the only one who’d fuck him like this. Red is so deep in him Sans can practically feel him in his throat, angled just right. He just doesn’t _stop_.

Red already got off tonight. (Don't think of the broken open, gratified noises Red makes when he's fucked. Don't think about whether they’re the same ones he makes for Edge. Don't.) He's probably gotten laid every night Sans was staring at his ceiling and having sadsturbation. Red’s not half as fucked up and desperate as Sans is, although judging from the roughness of his breathing and the way his hand shakes where it’s covering Sans’s mouth, he’s still getting off on this hard. That’s something, anyway.

Sans is trembling, so tense it aches, trying to eke a quiet, polite orgasm out of this. He’s running out of gas, slowing down, just little bursts of energy where he pushes back against Red all out of rhythm. Every one of Red’s thrusts rocks through him, making him burn brighter, getting him closer, but he’s not usually able to come just from being fucked. His grasp on Red’s hip weakens until he’s just sort of pawing at him. The next noise he makes against Red’s hand is too close to a whine.

Red’s fingers flex where they’re resting on Sans’s mouth, pulling his head further back, stretching his throat out long. When Red bites the back of his neck, Sans veers close enough to coming that he can taste it. His body rides the edge for several long, long seconds and then shoves him back over onto the wrong side, only barely receding but not enough to give him some actual respite. The breath sobs in his throat. Even with Red’s hand over his mouth, he’s being too loud. 

The kiss Red presses to Sans’s shoulder would almost be sweet if it wasn’t for the rest of what he’s doing to Sans, and it’s that one little thing that breaks him. He lets go of Red and shoves his hand between his legs, finding his neglected clit. 

“Yeah,” Red breathes, nearly purring. “That’s right. Lemme feel it.”

Sans presses further back into him, full-body, like he can back a safe distance away from the orgasm that’s about to crush him. His hands are shaking and his clit is slippery because he’s ridiculously wet, his body is really enthusiastic about this whole penetration thing, but he only has to fumble his way through stroking it a few times. Then the pleasure catches in him, a spark to a bonfire. 

When he comes, it’s too much to leave room for anything else in his head. No hesitation, no fatigue, no stubborn ache in his chest, no cold. Just Red, using him, holding him together. Red keeps moving in him, dragging the sharp pleasure out into something longer and sweeter and more bearable, until Sans feels Red’s thrusts stutter and then the heat of Red’s come in him. Warmth washes over his body, his soul, and rolls him under.

Sans takes a shortcut from one minute to another, only void between. When he comes back, Red is easing out of him. The mute, complaining noise Sans makes isn’t muffled at all. The lower half of his face is sweaty-hot where Red’s hand was. His jaw aches. All of him aches, actually, but he’s too limp and wrung out to care much.

Red curls against Sans’s back, stroking his hip with a thumb. His body is an anchor. He’s purring softly again. Quietly, he says, “You with me, buddy?”

“Mnn,” Sans says. Where else would he be? He tried to stay away but oops, here he is again, horizontal on Red’s mattress, come sliding out of him.

“Cool,” Red says, like that makes perfect sense to him. He nuzzles Sans’s throat. “Take your time. I can gloat about making you pass out later.”

“Ugh,” Sans says, because thinking of something appropriately snarky seems like too much effort when he’s still trying to get his breath back. He can hear his bones rattling. All this worry about keeping quiet and the two of them sound like a fucking maraca. It’s hilarious, suddenly, and Sans breaks into a hitching, airless laugh.

Red freezes. Sounding freaked out, he says, “Dude, are you--?”

The fact that Red thinks he made Sans cry with his dick is even funnier. Sans rolls over, shoving his face in the mattress, and laughs helplessly. It’s not quiet, but fuck it, let Edge think Sans is laughing at Red’s dick.

“Aw, fuck, I broke you,” Red says. Sans waves a hand at him, hiccuping, and Red moves so he can roll Sans onto his back. Sans squints up at him, tears in his eyes. Behind Red’s ribs, his soul is brighter again, like a recharged battery. Red studies his face with an expression that’s almost fond. “Punchy, huh?”

“I’m so tired,” Sans laughs.

“Yeah, I bet you are, dumbass,” Red says. Uncalled for. It’s not like Sans wants to be broken. Still, Sans laughs because there’s exactly jack shit he can do about it. Red rests his hand on Sans’s cheek, dragging his thumb across the dark circle under Sans’s left eyesocket. “Y’know, I always sleep better with company.” 

Sans yawns, still half-chuckling. “Good thing you got Edge, then.”

“It’s a big bed. Besides, Edge barely sleeps.” 

“Maybe you should give him crap about it instead of me.”

Red pats his cheek, close to a slap. “Stay. Boss makes a mean waffle and I make shitty coffee. I’ll blow you in the shower tomorrow morning. It’ll be great.”

It’s tempting. Too tempting to let himself take. “I can’t.”

“Yeah, I got it. Blah blah fucking blah, work in the morning, ‘my name’s Sans and I wish I had a nose so I could cut it off to spite my face.’”

Mildly, Sans says, “The falsetto’s unnecessary.”

Red leans down and kisses him once on the mouth. He doesn’t linger. “Figure you can sleep now?” 

“Yeah.” Sans’s shorts and hoodie seem a long way out of reach. When he half-heartedly stretches out an arm for them, Red snorts and snags them for him. Sans grins up at him. “Thanks.”

“Just another service I provide,” Red says. He shamelessly eyes Sans’s pelvis when Sans lifts his hips to get his shorts all the way on. “You’ve got my come all over you.”

An exhausted shiver rolls through Sans. He complains with less conviction than he should, “Don’t make it weird. ‘M too tired to shower.”

“I like it when you’re like this.” Red puts his hand on Sans’s chest, above his soul. It’s not until Red does that Sans realizes that the glow of his soul is still faintly visible even through the layers of his shirts. “For the record, sweetheart, I meant it when I said you can screw anybody you want.”

“Thanks, but I didn’t ask for your permission,” Sans says. Another yawn takes him.

Red ignores that. “It just means you’re gonna come back to me all riled up so I can get you off right.”

It’s hard to argue with that, considering, but Sans opens his mouth to start. Then he’s sitting on his own mattress across town, which kind of takes the wind out of his sails. He really doesn’t want to have this discussion about how he can get himself off just fine and he enjoys giving anonymous handjobs, thank you very fucking much, within earshot of Papyrus.

He gives Red the finger. It’s not particularly satisfying, but then his heart’s not really in it.

“Figured I’d drive you home,” Red says, voice pitched not to wake Papyrus if he’s actually sleeping for once. Red gets that like nobody else would. He pushes Sans’s shoulders flat against the mattress, like he needs assistance figuring out how to use a bed. “Now go to sleep before I choke you out. I ain’t your fucking babysitter.”

Sans doesn’t resist. The familiarity of his mattress, the way certain springs dig into his spine and how it’s molded to his body after years of use, the smell of his room and the faint nighttime sounds of the house (not like the one in Snowdin but almost comfortable by now), triggers some chemical in his brain that he can finally crash. He sighs and rolls onto his side, giving Red his back. He’s almost out already, even with Red still leaning over him like some weird vulture. He can feel the pressure of Red’s eyes, watching him. Watching over him. Red’s hand settles on the back of his neck, thumb stroking the cartilage between his vertebrae. He thinks maybe Red knew he was planning to stay gone after all. Then he’s asleep.

Red’s gone when he wakes up in the morning. It takes twenty minutes to scrub off the dick he drew on Sans’s forehead in permanent marker.

**Author's Note:**

> Content notes: Sans has extremely one-sided, sleep-deprived casual sex as a coping mechanism.


End file.
